1. Technical Field
The invention relates to a valve for use during inflation of inflatable devices. More particularly, the invention is an inlet check valve for use either singularly by itself or twined with another valve, of similar or different construction, to form a manifold that in either case is used during inflation of inflatable devices such as life rafts or escape slides. Specifically, the invention is a low profile, free rotating inlet check valve that freely rotates about its connection with the inflation device so as to make packing and folding of the inflation device easier, to eliminate or minimize the damage to the inflation device or the inlet check valve during packing and inflation, and to allow for uninhibited or minimally interfered inflating of the inflation device from a packed and folded position to an inflated and open position. The invention is further a manifold having multiple low profile, free rotating check valves connected together via a coupling or "Y" fitting.
2. Background Information
The popularity of ships, boats and other large water vessels for both passenger and cargo travel over the world's vast navigable waters, many of which are far from land, presents a problem should the ship become disabled, or worse sink. In response, some form of life preservation for the passengers and crew is preferred if not required, preferably where the passengers and crew remain out of the water. As a result, ships include small vessels in case of peril to the main ship so that the passengers and crew of the ship may escape to interim safety until help arrives. For many years these small vessels were either nonexistent or were rigid structures such as small boats. In addition, storage of these small boats consumed large spaces and added significant weight to the overall main ship, both of which were undesirable.
Furthermore, with the invention of aircrafts and overseas travel early in this century, an additional need arose for escape hatches or slides that were compact. Absent extreme compactness, these escape hatches or slides were not practical due to the nature of aircraft flight which requires light weight and small volumetric dimensions in all areas in order to achieve lift and economically remain airborne.
These needs were answered with the invention of the inflatable life raft and inflatable escape slide. Since the inception of the inflatable life raft during World War II, most raft builders have used either readily available single inlet check valves or a manifold with "twined" inlet check valves molded therein to supply pressurized fluid, typically gas such as carbon dioxide, into a raft or slide's expandable chambers such as buoyancy tubes on a raft.
The inlet check valve was designed to achieve high volume fluid input through the valve and into the inflatable chamber connected therewith, while prohibiting fluid flow back through the valve once the inflatable chamber has reached an equilibrium pressure with the incoming fluid. The result of this inlet "checking" is a one step operation of supplying the pressurized fluid resulting in a rapidly inflated inflatable chamber which once inflated closes itself off.
In general, the current state of the art involves inlet check valve designs requiring the molding of a rubber flange over the inlet check valve that is usually brass to obtain a permanent metal to rubber bond or seal. The rubber flange is in turn permanently cemented to the tube fabric on the raft or slide. The inlet check valve is therefore permanently affixed to the inflation device.
Current inlet check valves of this design have generally performed the needed checking function. However, these current inlet check valves which are constructed largely from brass are both bulky and heavy which is contrary to the above referenced critical elements of small size and light weight. This bulkiness and heavy construction often creates packing and deployment problems.
In addition, the inlet check valves are of a rigid and permanent design that requires complete removal of the valve for repair or replacement. This removal or repair is often difficult and may require the cutting out of flange cemented to the inflation device in which the valve is permanently fixed. This replacement involves recementing of the flange to the fabric--a labor intensive, time consuming, and as a result, expensive process.
Also, current inlet check valves also often require a special poppet removal tool for field servicing of the valves. This tool requirement can further be somewhat of a nuisance.
Often, it is desirable to use one pressurized fluid source to simultaneously inflate more than one inflatable chamber. For instance, some inflation devices are of a bulkhead design, that is the inflatable device includes internal walls defining more than one inflatable compartment therein. It is desirable to simultaneously inflate the adjacent compartments using one pressurized fluid source. This is achieved by a manifold having two inlet check valves molded therein in a manner often referred to in the industry as "twined".
In general, the current state of the art for manifolds is similar to inlet check valve assemblies consisting of an inlet check valve and a rubber flange except the manifold is significantly larger in that it contains multiple valves fluidly connected together and fully enveloped in the manifold which includes the flange that is cementable to the fabric. Specifically, the manifold includes a pressurized fluid inlet coupled to multiple valves with outlets connectable to inflatable chambers where the entire assembly is enveloped in rubber or other polymer except for the inlet and outlets.
These manifolds are very bulky and quite rigid, and have thus been a continual source of packing difficulty and poor inflation performance. As to the packing, it is often difficult to fold the deflated inflatable device into a small, compact and readily inflatable package because of height and overall size interference from the large and bulky manifold. As to inflation performance, the bulky and rigid valve often impedes unfolding during deployment, thereby causing or increasing stresses within both the inflation device and the manifold with check valves therein as the inflatable device overcomes this impediment. These stresses may result in damage to the manifold or inflatable device.
In addition, should one of the inlet check valves need repaired or replaced, as described above, this replacement involves removal of the entire manifold and recementing of a new manifold to the fabric.
A need exists for an improved inlet check valve and/or manifold with multiple inlet check valves therein where bulk and rigidity of the assembly are reduced thereby improving packing and deployment as well as reliability.